Resistive random access memory (RRAM) is considered a promising technology for electronic synapse devices or memristors for neuromorphic computing as well as high-density and high-speed non-volatile memory applications. For instance, in neuromorphic computing applications, a resistive memory device can be used as a connection (synapse) between a pre-neuron and post-neuron, representing the connection weight in the form of device resistance. Multiple pre-neurons and post-neurons can be connected through a crossbar array of RRAMs, which naturally expresses a fully-connected neural network.
In order to make a large-scale crossbar array, each cross point in the array must have a high resistivity (or low leakage current). Otherwise, voltage drop across the metal lines becomes significant.
However, it is typically very difficult to maintain high device resistivity after filament formation for Conductive Bridging RAM (CBRAM) or Oxide-based RRAM. In addition, filamentary RRAMs have high device variability.
Non-filamentary RRAM (e.g. PCMO) can mitigate these drawbacks. However, current state of the art non-filamentary RRAM employ exotic materials which are not complementary metal oxide semiconductor (CMOS) compatible.
Therefore, non-filamentary RRAM devices that are CMOS-compatible would be desirable.